Taking stock of national climate policies to evaluate implementation of the Paris Agreement

Many countries have implemented national climate policies to accomplish pledged Nationally Determined Contributions (NDCs) and to contribute to the temperature objectives of the Paris Agreement. Using a public policy database and a multi-model scenario analysis, the study shows that current policy implementation leaves a median emission gap of 22.4–28.2 GtCO2eq by 2030 relative to cost-optimal pathways consistent with well-below 2 °C and 1.5 °C. Full implementation of NDCs would reduce this gap by about one third. Countries either fail to reach their NDCs with current policies (implementation gap) or have an ambition gap relative to optimal well-below 2 °C pathways. Accelerated deployment of renewable technologies is needed globally, with efficiency improvements particularly important in emerging and fossil-fuel-dependent countries.

Mark Roelfsema, Heleen L van Soest, Mathijs Harmsen, Detlef P van Vuuren, Christoph Bertram, Michel den Elzen, Niklas Höhne, Gabriela Iacob, Volker Krey, Elmar Kriegler, Gunnar Luderer, Keywan Riahi, Falko Ueckerdt, Jacques Després, Johannes Emmerling, Stefan Frank, Oliver Fricko, Matthew Gidden, Florian Humpenöder, Daniel Huppmann, Shinichiro Fujimori, Kostas Fragkiadakis, Keii Gi, Kimon Keramidas, Alexandre C Köberle, Lara Aleluia Reis, Pedro Rochedo, Roberto Schaeffer, Ken Oshiro, Zoi Vrontisi, Wenying Chen, Gokul C Iyer, Jae Edmonds, Maria Kannavou, Kejun Jiang, Ritu Mathur, George Safonov, Saritha Sudharmma Vishwanathan